D&D 5E – Drowning

I haven’t posted here in a while. I have been working on 5E Ship-to-Ship combat rules. They will be finished soon. In the mean time here is part that may be of general interest.

Drowning Rules for D&D 5E

Falling Off the Ship

Rough water adds 5 to all the following DCs except for saves made when more than 5 feet under the surface. Flotsam or other floating items grant advantage to saves to stay afloat.

The Fall

This can be hazardous to your health. If you fall overboard you will splash down 1d6+5 feet from your ship. If you are pushed overboard you will fall 2d6+5 feet from your ship. If you jump or dive into the water you can enter the water at any point up to the maximum distance you can jump (refer to the Jumping rules in the Player’s Handbook). If you fall or are pushed overboard, you must succeed on a DC 10 Dexterity (Acrobatics) check to enter the water without damage. Otherwise you receive 1d6 hit points damage from the fall.

Swimming

Each foot you swim cost you one extra foot of speed. If you are within 5 feet of a moving ship (or one that has been involved in a ramming or grappling maneuver), you must make as DC 10 Strength (Athletics) check. Failure means that you cannot move this round, you are using all of your strength to simply keep your head above the waves. Once you reach the ship, you must make as DC 15 Strength (Athletics) check to climb back onto the ship. Failure results in you falling back into the water.

Underwater

You can swim underwater as long as you can hold your breath (see “Drowning” below). Your underwater swimming speed is the same as your surface swimming speed. You can swim straight down at half that speed. You can swim straight down at 15 feet per round if holding the equivalent of medium armor, or 25 feet per round if holding the equivalent of heavy armor. If unencumbered, you can swim straight up at 20 feet per round.

Armor

In general, heavy armor is not terribly common on ships. The weight tends to be the most prohibitive factor – falling overboard in 65-pound full plate normally results in death. Occasionally, combat Infantry will don light or medium armor for a battle, but most of the time sailors go unarmored. A lucky few (usually the PCs and important NPCs) have magic items that improve their AC, but most sailors rely on their natural Dexterity.

Light Armor

Attempting to swim while wearing light armor requires that you make a DC 10 Strength (Athletics) saving throw each round. Failure means you have a speed of 0 as you go under water for that round and loose one carried item, shield or weapon (your choice as to what you drop).

If you choose to remove your armor after entering the water, it will take one minute (10 rounds). A successful DC 15 Dexterity (Acrobatics) save will cut that time in half. During this time you cannot swim or take any other actions. You make a DC 10 Dexterity (Acrobatics) saving throw each round. Each round that you succeed you keep your head above water and counts as one round of the rounds required to remove your armor. Failure means that you went under water this round and made no headway in removing your armor. After 3 failures you receive one level of exhaustion.

Medium Armor

You can attempt to swim while wearing medium armor, but you must make DC 15 Strength (Athletics) saving throw each round. On a success, if you are on the surface at the beginning of the round, you stay on the surface. Each foot you swim cost you two extra feet of speed and you can take no other actions besides shouting and stowing a weapon. Failed save means you sink 10 feet and lose any still-carried shields or weapons. On the round following a failed save you are under water. After that, on a successful save you can swim toward the surface at a rate of 15 feet per round. On failure you sink another 10 feet.

You can attempt to remove your armor, but you will be sinking at a rate of 10 feet per round during this time. It normally takes 1 minute (10 rounds) to doff your armor, but a successful DC 15 Dexterity (Acrobatics) save will cut that time in half. Without your armor you can swim toward the surface at a rate of 20 feet per round.

Heavy Armor

You cannot swim while wearing heavy armor, giving you an effective speed of 0. Whenever you are in water, you lose any carried shields and weapons and begin to sink. You make a DC 25 Strength (Athletics) saving throw each round. Success keeps your head above water, or if you start the round under water you can swim 15 feet toward the surface. You can take no other actions. Failed save means you sink another 20 feet.

You can attempt to remove your armor, but you will be sinking at a rate of 20 feet per round during this time. It normally takes 5 minutes (50 rounds) to doff your armor, but a successful DC 15 Dexterity (Acrobatics) save will cut that time in half. Without your armor you can swim toward the surface at a rate of 20 feet per round.

Drowning

After 1+(con bonus) minutes of holding your breath underwater you fall unconscious, your hit points fall to 0, and you can then survive for a number of rounds equal to your Constitution modifier (minimum 1 round). After that, you begin making your death saving throws as per the standard rules. However, if you become stable there is a problem. If you are still under water you can’t remain stable. So you must start making death saving throws again. This continues until you die unless you are saved in some way.

Excellent catch!
I revised the post. Thank you very much. Now I need to go back and change that in my Ship-to-ship combat rules “Nautical Adventures”.
If you find any other errors in this or any other of my posts, please don’t hesitate to tell me.
Thanks again,
Ronny

i had read somewhere that if you are caught by surprise that you cannot hold your breath in the same manner in which you were prepared to hold your breath so that instead of the 1+con modifier in minutes it becomes 1+ con modifier in rounds.

It isn’t in the DMG, but thank you for pushing me on this. As a result of my research I have edited my original post – In the drowning section I added “, and you can then survive for a number of rounds equal to your Constitution modifier (minimum 1 round).”

As far your original post regarding how surprise effects how long you can hold your breath, it doesn’t look like it is addressed in either the PHB or the DMG. I think I wall use a general house rule that whenever you are unable to prepare to hold your breath by taking in a lung full of air, your drop to 0 HP after a number of rounds equal to your Constitution modifier (minimum 1 round). Simply being surprised is not enough to prevent you from taking a breath.

Here is what it says in the PHB:

“A creature can hold its breath for a number of minutes equal to 1 + its Constitution modifier (minimum of 30 seconds). When a creature runs out of breath, it can survive for a number of rounds equal to its Constitution modifier (minimum 1 round). At the start of its next turn, it drops to 0 hit points and is dying.”
“For example, a creature with a Constitution of 14 can hold its breath for 3 minutes. If it starts suffocating, it has 2 rounds to reach air before it drops to 0 hit points”

With this added in the official Errata: “If you run out of breath or are choking, you can’t regain hit points or be stabilized until you can breathe again.”

No.
But exactly how to handle the situation will by up to the DM and will depend a lot on why they are unconscious.
Here is how I would do it.
I would let an unconscious character whose current hit point total was above 0 hold his breath for the same amount of time that I would if he was conscious. If he was unconscious as the result of a sleep spell, for instance, it reads in part that the target “falls unconscious until the spell ends, the sleeper takes damage, or someone uses an action to shake or slap the sleeper awake.” I believe that it is in the spirit of the rules that this would also apply to any level of violence as slapped or shaken would do. I think that attempting to take a breath underwater would be enough of a shock to become conscious. This would also apply to most of the time when a character is asleep or unconscious for whatever reason.
If he is unconscious because of an Astral Projection spell, being underwater has no effect because the body he leaves behind doesn’t require air.
If he is unconscious because another character knocked him out, then he is already at 0 hit points, but stable. In that case or any time that he is unconscious at 0 HP and stable, if he is underwater he is no longer stable and will have to start making death saving throws as I said under “Drowning” in my original post.